<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>边框练习</title>
		<style>
			div#circle{
				width: 200px;
				height: 200px;
				border: 1px solid #fd77b8;
				background-color: #fd8d2a;
				border-radius: 50%;
			}
			div#triangle{
				 width: 0;
				 /* border-left: 50px solid transparent;
				 border-right: 50px solid transparent;
				 border-bottom: 50px solid rgba(0, 0, 255, 0.3); */
				 /* 两行： 全部设置为透明色，上面的三角设置颜色*/
				 border: 50px solid transparent;
				 border-top-color: rgba(255, 1, 196, 0.3);
				 }
				 input{
				 outline: 1px solid red;
				 outline: 0; /* 去掉边框效果，通配选择器中 */
			}
		</style>
	</head>
	<body>
		<div id="circle"></div>
		<div id="triangle"></div>
		文本框
	</body>
</html>